Answer:
Given that,
The number of grams A of a certain radioactive substance present at time, in years
from the present, t is given by the formula
a) To find the initial amount of this substance
At t=0, we get
We know that e^0=1 ( anything to the power zero is 1)
we get,
The initial amount of the substance is 45 grams
b)To find thehalf-life of this substance
To find t when the substance becames half the amount.
A=45/2
Substitute this we get,
Taking natural logarithm on both sides we get,
Half-life of this substance is 154.02
c) To find the amount of substance will be present around in 2500 years
Put t=2500
we get,
The amount of substance will be present around in 2500 years is 0.000585 grams
Answer:
see explanation
Step-by-step explanation:
Given
a = ![\left[\begin{array}{ccc}3\\2\\\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D3%5C%5C2%5C%5C%5Cend%7Barray%7D%5Cright%5D)
To obtain -3a multiply each of the elements of a by -3
3a = ![\left[\begin{array}{ccc}-3(3)\\-3(2)\\\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-3%283%29%5C%5C-3%282%29%5C%5C%5Cend%7Barray%7D%5Cright%5D)
= ![\left[\begin{array}{ccc}-9\\-6\\\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-9%5C%5C-6%5C%5C%5Cend%7Barray%7D%5Cright%5D)
To obtain 1.5a multiply each element by 1.5
1.5a = ![\left[\begin{array}{ccc}1.5(3)\\1.5(2)\\\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D1.5%283%29%5C%5C1.5%282%29%5C%5C%5Cend%7Barray%7D%5Cright%5D)
= ![\left[\begin{array}{ccc}4.5\\3\\\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D4.5%5C%5C3%5C%5C%5Cend%7Barray%7D%5Cright%5D)
Answer and explanation:
Given : Strands Copper wire from a manufacturer are analyzed forstrenghth and conductivity. The Results from 100 strands are as follows :
Strength Strength
High Low
High conductivity 74 8
Low conductivity 15 3
To find :
a) If a stand is randomly selected, the probability that is conductivity is high and its strength is high
The favorable outcome is 74
The probability is given by,
b) If a stand is randomly selected, the probability that its conductivity is low or strength is low
Conductivity is low A= 15+3=18
Strength is low B= 8+3=11
Conductivity is low and strength is low 
Probability is given by,
c) Consider the event that a strand low conductivity and the event that the strand has a low strength. Are these tow events mutually exclusive?
Since the events the stand has low conductivity and the stand has low strength are not mutually exclusive, since there exists some cases in which both the events coincide. i.e. Intersection of both the events exists with probability 0.03.
Answer:
22
Step-by-step explanation:
it is epuivalet
